Proof that with the right software anything can “fly” (SN6 test hop from SpaceX)
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I have always been a rocket/space enthusiast (was planning to be an Astronaut until my vision stopped being 20/20) and one of my favorite books on the subject is Sutton's "Rocket Propulsion Elements." One of the things that was clear from this text was just how difficult it is to manage the thrust of a rocket engine. Many engines had 2 or maybe 3 "settings" but the continuously variable thrust of the Raptor was pretty much considered "impossible" for a long time.